XBRL context and unit errors
Find the source location, repair the generating software and rerun the chosen validation layers. Scope: partial XBRL 2.1 / iXBRL 1.1 preflight.
Repair a missing reference at its source
In the fictional context-error example, the numeric Assets fact on line 11 has contextRef="missing". The resources block defines c1, not missing. XB-CONTEXT points directly to the fact rather than asking you to search every context manually. Restore the intended contextRef from the exporter’s context map or create the intended context once. Do not blindly copy c1 into every fact: a different reporting period or dimensional breakdown may require a different context even when a copied reference makes the structure check pass.
A context reference must resolve uniquely to an XBRL context element. An element with the right id but the wrong namespace is insufficient. Duplicate XML ids make references ambiguous and trigger XB-ID. In iXBRL resources, a unit reference similarly needs a unique local XBRL unit. The numeric nonFraction example references u1, whose measure is EUR. Changing unitRef to an absent identifier demonstrates XB-UNIT. This is a reference-presence check only. It does not prove that the chosen measure is appropriate for the concept or that a divide unit is semantically correct.
Let Arelle check the reporting meaning
The pinned offline Arelle integration owns semantic context, unit and dimensional validation. It also requests duplicate-fact checks and calculation validation using the selected round-to-nearest mode. Different contexts can be equivalent despite different ids, and repeated numeric facts can agree at different reported decimal precision. A string comparison of ids or fact values cannot decide these cases. The browser therefore does not pretend to implement a second XBRL processor. Review the native validation code in your local Arelle report with its source location and regenerate the affected facts.
Calculations require the applicable licensed taxonomy relationships and consistent numeric facts. Merely supplying a decimals attribute is not evidence that all calculations were evaluated. Formula processing is another explicit scope: no formula pack is bundled, and no absence of formulas is inferred from a clean browser check. Use authorised local rules, select formula execution in the adapter, inspect the execution evidence and keep unsupported or unexecuted checks visible in the report.
Read the layer before changing the report
The browser preflight and Arelle answer different questions. A local structure check can locate a reference that points to nothing. It cannot establish whether the referenced context has the correct entity, reporting period or dimensional meaning. The report therefore separates XML syntax, supplied XSD, independent structure checks, plausibility, package references and imported Arelle evidence. A successful result within one layer does not imply success in the others. The overall result remains incomplete when the applicable filing profile is not fully checked.
The independently authored examples use a fictional issuer and a small original taxonomy. No real amounts or issuer identifiers are needed to reproduce the error. The valid structure example deliberately reports XSD and Arelle as not executed. The teaching-only XSD constrains an original data-demo attribute on the XHTML root. Removing that attribute demonstrates a known schema error on line 1. This is a useful check of the separate XSD execution path, not a claim that the teaching schema validates official XBRL or XHTML. To test an official schema you need the complete original dependencies and sufficient concrete processing rights.
Bring local evidence without losing its scope
The separately downloadable adapter requires Arelle 2.47.4, exact SHA256 values and a provenance record for every artifact in a closed local directory. It requests XBRL validation, all duplicate facts and round-to-nearest calculations. Formulas run only when explicitly selected for rules you may process. The adapter disables networking and persistent configuration, limits memory and CPU, and loads no third-party plugins. It rejects absolute discovery references and incomplete local dependencies. It is intended for the documented Linux/Python local workflow, not as a general sandbox for executing arbitrary plugins.
Import the adapter JSON beside the same unchanged report. Original-byte hashing catches changes in line endings as well as changes in content. A report produced for another document, another profile or another engine configuration is rejected. With multiple documents, this first interface compares the imported evidence separately with each file; it does not distribute one successful report across a whole batch. Imported results are user-supplied evidence rather than an independent server attestation. Missing dependency errors, truncated logs and incomplete engine runs cannot establish passing semantic coverage.
Rights and privacy boundaries
Arelle core uses Apache-2.0; its dependencies and plugins have separate notices. The license of an engine does not license its inputs. XBRL core schemas fall under the Software Notice rather than just the document license. The ESMA ESEF 2025 page reserves IFRS rights and restricts commercial reuse; its EEA nonassertion must not be treated as a general commercial SaaS license. No IFRS/ESEF package is bundled or automatically fetched. Public access, free download, BYO and runtime-only processing do not remove these restrictions.
Browser checks remain on this device. The interface does not send XML, amounts, fact values, issuer IDs, filenames or native Arelle log messages to analytics. Its fixed funnel events record the action and a coarse outcome. JSON and CSV exports happen only on your action and may contain local provenance and source locations, so store them according to your reporting workflow. The first release gives no full ESEF, auditor, tax authority or publication acceptance approval. Correct the generating software, rerun the same chosen layers and use your authorised filing process for final acceptance.
Primary sources
Pinned Arelle command-line options · Official iXBRL specification index · Official XBRL instance schema · XBRL copyright and Software Notice boundary · ESMA ESEF 2025 rights · Arelle license and dependency notices. Rechecked 6 November 2026. Explanations and examples independently written; no protected taxonomy rules copied.